replacing intake tube

[Big K]

i want to replace my intake tube with with a smoother, less restrictive tube. but what do i do about the hose that connects from my intake tube to my engine oil?

 

[Tony91Sport]

Put a small k&n breather on it, like this one.


http://store.summitracing.com/produ...4KFESP&p=A6ED1C74-3612-11D3-949D-080009FC5B5F

Tony
91 Sport 2WD

 

[jimbo74]

careful!!! i live in california and putting on a breather like that will get you a ticket!!!

 

[Big K]

does the hose just rip off the intake tube, and the breather is just placed on to cover it?

 

[Big K]

also...do you know which part number is right for a 99 explorer?? thanks for the help!

 

[Tony91Sport]

I cant say which one will fit, but you can measure the diameter of the one coming off the oil filler tube. I would cap the other one off securely or it might screw with your Mass Air Flow readings.

Tony
91 Sport 2WD

 

[mdrut]

Careful.. that small hose is pulling pressure out of you crankcase..Going to mess up the emissions, if your not careful.

 

[Roger Babich]

"Careful.. that small hose is pulling pressure out of the crankcase..Going to mess up the emissions, if your not careful. "

I thought this small hose was providing filtered air into the crankcase, not allowing pressure to come out there. The PCV valve in the intake is pulling air thru the crankcase and the small hose from the air cleaner is allowing filtered to enter the crankcase via the oil fill spout. The PCV is sized to provide the proper amount of airflow out of the crankcase into the engine, so whether the small intake hose is connected to the air cleaner or has it's own filter shouldn't make any difference.
Roger Babich

 

[Big K]

ok what exactly is a PCV valve and crankcase? and if i made a less restrictive intake hose would i be able to connect the small hose to it? thanks for the help!

 

[Roger Babich]

"ok what exactly is a PCV valve and crankcase? and if i made a less restrictive intake hose would i be able to connect the small hose to it?"

The Positive Crankcase Ventilation (PCV) valve is a small steel can with a hose bib on one end and a hole in the other. It is a one-way valve that will rattle when shaken. If it doesn't rattle spray some carb cleaner in it to loosen the valve. The end with the hole in it usually goes into a rubber grommet on a valve cover. This hole is sized to provide a certain amount of air into the engine so it is important to use the valve specified for a particular engine. Engine vacuum pulls air thru the PCV valve, but since it is one-way will not let air flow back thru it into the crankcase. The hose connected to the barbed end usually connects to the base plate of a carb or throttle body. Air is drawn by the engine thru the PCV valve from the oil pan/crankcase area, but air must come in from somewhere or the oil pan will collapse or gaskets will get sucked in. Another hose on the other valve cover is connected to a filtered fresh air source. All of this prevents oil vapors from the crankcase from escaping into the atmosphere, by sending the oil vapors into the engine to be burned. The small hose from the oil fill spout to the air cleaner tube can be replaced with it's own air filter (frowned upon by smog checkers as a "modification" although in my view "works just as well") or can be reconnected to a more free flowing air tube, as long as the connection is after the filter, so unfiltered air does not go thru the crankcase. And your other comment is right, it does take away from air flow to the throttle body. This is actually a good system that does not cost horsepower when set up properly.
Roger Babich
'92 Explorer
'77 E-150
'76 E-250
'72 Torino
'70 Mustang
'67 VW bus
'54 F-250
'30 Model A

 

[Roger Babich]

" The small hose from the oil fill spout to the air cleaner tube can be replaced with it's own air filter (frowned upon by smog checkers as a "modification" although in my view "works just as well") or can be reconnected to a more free flowing air tube, as long as the connection is after the filter, so unfiltered air does not go thru the crankcase. "

I think my comment about "connected after the air filter" may be incorrect. It should be connected after the MAF. The air thru a PCV is part of the "mass" of air getting into the engine and should be measured by the MAF. It may not be enough to make a difference, but it may not be a good idea to put a filter on the small hose going into the oil filler. Has anyone who has replaced the small oil filler hose with a small filter noticed any difference in engine performance? If this was done at the same time as modifying the air tube from the MAF to the throttle body it may be hard to notice. The MAF will not be measuring the air flow thru the PCV into the engine and performance and/or mileage may suffer.
Roger Babich

 

[Big K]

man this mod is becoming overwhelming. I get too caught up in trying to get the most out of my engine that i always forget to consider what may be affected in the process. Thats where you guys come in! thanks for the help!